Sheffield tram-train
The cost of Sheffield’s heavily delayed tram-train project has soared by 400% in the past five years, according to a report from the National Audit Office. TOM INGALL investigates why
It has been a rough ride. RAIL explains why the cost of Sheffield’s heavily delayed tram-train project has soared by 400% in five years.
At Rotherham station the UK’s tram-train pilot project is making its presence felt. The station is on College Road, which crosses the railway below. To install the overhead line equipment (OLE) that will power the tramtrain vehicles, the bridge needs to be raised. While passengers and pedestrians navigate temporary walkways, orange-clad contractors are working away behind wire fences. It’s a job Network Rail didn’t anticipate having to do.
It’s no secret the service is late starting - it’s anticipated it will finally commence in summer 2018, some two and a half years after the initial opening date came and went ( RAIL 828).
But we now know that not only was the schedule optimistic, the budget was woefully off course, too. The National Audit Office (NAO) published a report in early July examining the modifications required to the rail network to facilitate tram-train. When the project was signed off in 2012, they were expected to cost £15 million. The expected cost upon completion is now £ 75.1m.
Beside the temporary fencing, an engineer who had read the report admitted that it was “very disappointing”. It is more than that - it forensically details the chronology of the project from outline scheme to half-built reality, with costs rising and the Benefit: Cost Ratio (BCR) collapsing along the way.
Very late and considerably over budget, tram-train is a project which hasn’t even had a chance to be accepted by the travelling public before its reputation has been seriously tarnished.
Clive Betts, the Labour MP for Sheffield South East, first asked the National Audit Office to get involved. He says: “I thought it was an appalling piece of project mismanagement by Network Rail. It is staggering that something is so far over budget and is so late. It is impossible to understand how they have managed it so badly.”
According to the NAO report, approval to proceed was given by the Treasury in May 2012, after a lengthy gestation. Concerns were expressed about an apparent poor value for money that the scheme offered. The Department for Transport itself assessed the BCR at a ‘low’ 1.0, but an argument that it should be seen as a genuine trial - with the potential for wider strategic benefits if rolled out to other cities - carried the day.
Because heavy and light rail have differing technical and safety standards, bringing the two together would be a key challenge for the pilot. In practice this has meant looking at signalling, wheel profiles, different loading gauges, the ride quality of the lighter tramtrain vehicles, and (crucially) the traction power supply for the vehicles.
However, the actual extension to the tram network is relatively short.
To recap, a new chord line leaves the eastern corner of the existing Sheffield Supertram network close to the terminus at the Meadowhall Shopping Centre. It turns sharply towards Rotherham, and after a few hundred metres connects to Network Rail metals - the freight-only line which runs between Woodburn Junction and Rotherham. The line is single at this point, but soon doubles and joins a passenger line before arriving at Rotherham station.
The existing heavy rail platforms will receive low-level extensions to cater for the tramtrain vehicles, but this represents another concern for the pilot. Does a low-level platform encourage trespass? Could passengers waiting on it be at risk from exposed running gear from passing heavy rail vehicles?
Continuing onwards along Network Rail lines for another mile, the tram-trains will turn off onto a purpose-built spur and terminate adjacent to an out-of-town retail park. This will enable them to reverse at a purpose-built platform without causing a delay to through trains on the national network.
Network Rail estimated that delivering the necessary modifications to its infrastructure would cost £18.7 million, but that with efficiency savings that could be reduced to £15m. It agreed that figure with the DfT, and tram-train was duly added to the ‘to do’ list for the 2014-19 programme. But just two months after it was approved, the presumptions it was based on began to shift.
In July 2012 came the announcement that the Sheffield to Doncaster line was likely to be electrified at some point after 2019. As built, the tram-train OLE had to be able to deliver 750V DC, the same as the Supertram network. Now, in future it might need to deliver 25kV AC. The tram-train vehicles themselves could be specified dual-voltage, but there was no such ‘off the shelf’ solution for the OLE.
As detailed in RAIL 828, this has meant developing new equipment. Rob Cairns, Regional Director of Infrastructure Projects at Network Rail, explained: “We simply can’t achieve a DC application with an AC proprietary system without developing new products like double insulation, things that will protect the AC system from the effects of DC voltages. That’s what stopped us taking products from the catalogue and forced us to
We now have an expert team in place, and they took their time to get to a stage where we now have a definite plan in place in terms of cost and time. We look forward to handing over the network to Supertram next year. Nick Sandham, Head of Communications for Network Rail’s London North Eastern and East Midlands Route
think again. The products themselves might look straightforward, but the process we have to get through to prove they are safe is complex.” As well as time-consuming!
In late 2013, as the outline design work was concluded, the extra work to the OLE had pushed the price up. NR now estimated a cost of £ 31.8m.
As the DfT had by now agreed the vehicle procurement process with South Yorkshire Passenger Transport Executive, the project timetable was reset for the service to begin in early 2016.
Twelve months later, as construction negotiations began with a contractor, that price estimate became £44.9m… and then £48.6m. Besides the work to allow future conversion of the power supply, the condition of existing assets was cited as a reason, but the NAO also finds that “the confirmed characteristics of the tram-train vehicles differed from the agreed vehicle design assumptions used in Network Rail’s early infrastructure designs”.
For the first time, questions were asked about whether or not to continue. The Permanent Secretary of the DfT concluded that it should, as the rationale remained unchanged.
Given that NR was reclassified as a public body in September 2014, it could not increase borrowing to pay for the growing costs of tram-train. Instead, the DfT agreed to fund the cost of the works and changed the project governance structure.
Sheffield South East MP Betts believes it was right to authorise the project in the first place: “I think it should have been. Ministers